News | Published May 7, 2013

When struggling to hear may seem like the onset of dementia

An elderly patient came to the office of Leslie A. Purcell, AuD, Mount Nittany Physician Group Ear, Nose & Throat/Audiology, because his hearing aids did not seem to be working. “He was basically unresponsive to any attempt at communication, and his caregiver was concerned about his change in mental status,” said Dr. Purcell.

It turned out his hearing aids needed repair. When Dr. Purcell did that and put them back into his ears, his face lit up and he had a 15-minute conversation. He was a totally different person. His mental status had not changed at all; in fact he was quite sharp. The change was that his brain was deprived from auditory input; therefore, he was responding inappropriately when spoken to and withdrawing socially. 

Dr. Purcell said that the brain is so preoccupied with translating sounds into words that there is no processing power left. “Often, it is difficult to determine whether the brain is not receiving the signal due to hearing loss or not processing the signal correctly, possibly due to the onset of dementia.”

She added, “Often people with hearing loss are playing a game of 'fill in the blanks' when listening. They are able to hear part of the sentence or sound of a word, but need to fill-in the parts they are missing due to their hearing loss. The brain is processing too much at once and often the individual is left behind in conversation. Many people become so exhausted at attempting to keep up with the conversation, they withdraw. This in turn, leads to the feeling of isolation that might be interpreted as dementia.” 

In a 2011 paper in The Archives of Neurology, Frank Lin, MD, an otolaryngologist and epidemiologist at Johns Hopkins School of Medicine, and his colleagues, found a strong association between hearing loss and dementia. The Baltimore Longitudinal Study of Aging found that the worse the hearing loss, the greater the risk of developing dementia. The correlation remained true even when age, diabetes and hypertension - other conditions associated with dementia - were ruled out.

This study indicates that the more hearing loss you have, the greater the risk for developing dementia. Dr. Purcell concurs and she believes hearing loss prevention is key. “You can prevent hearing loss by using hearing protection and by obtaining a regular hearing evaluation. By addressing the hearing loss sooner than later, you keep the cognitive system functioning and help to prevent that decline.”

Dr. Purcell said, “There is much research on the effects of auditory deprivation and recovery of hearing function. When an individual has hearing loss there are areas of the auditory nerve that are not stimulated by common sounds and the nerve can atrophy. It is better to act on suspected hearing loss sooner rather than later because hearing really is a 'use it or lose it' function.”